Update README.md
Merge pull request #38 from bulatb/patch-1

Update README.md
Updated Gliese 667. Sources:
http://www.eso.org/public/news/eso1328/
http://adsabs.harvard.edu/abs/2008MNRAS.389..925T
http://adsabs.harvard.edu/abs/2001A&A...367..521P
Updated typos and new tags.